I am not sure what the lump is, obviously you are keeping an eye out for any distress or problems.
As a side issue i put my mothers with chicks in a separate area from the rest of the flock, Mums and babes are fed chick crumbs, i dont put in anything else...well, water of course. That way the chicks don't get a hold of anything they shouldn't. The hen wont be laying so its safe to give her chick crumbs (which are not to be fed to laying birds, or rather their eggs should not be eaten) i feed my hens the Farmgate range...they wont eat Allan and Page etc.
The rules for feeding may be different for other ranges of feedstuffs.
HTH Emma x